A few years ago we reported here that Professor Philip Moriarty of the University of Nottingham in the UK had received a substantial grant to experimentally investigate the possibility of diamond mechanosynthesis, testing the theoretical proposals made by Robert Freitas and Ralph Merkle. The official announcement of the grant lists the Institute for Molecular Manufacturing, the current institutional home of Freitas and Merkle, among the project partners. We are indebted to Brian Wang for informing us of an interview of Philip Moriarty by Sander Olsen published yesterday on Next Big Future. This is a very substantial interview in which Moriarty presents their latest work mechanically manipulating dimers of silicon on a Si(100) surface (complete with lengthy video of the results!), explains why silicon is much easier to work with than diamond, expresses confidence in the eventual ability to instruct a computer to built a three-dimensional nanostructure atom-by-atom, thus validating key aspects of Drexler’s mechanosynthesis proposals, but also expresses skepticism that such abilities could be scaled up to develop macroscale molecular manufacturing or to produce hordes of medical nanorobots as proposed by Freitas and cited by Ray Kurzweil. You should read the entire interview because there is much more than I can excerpt or summarize here. From “Philip Moriarty discusses mechanosynthesis with Sander Olson“:

University of Nottingham physicist Philip Moriarty is one of the few scientists who has been able to do extensive research into molecular mechanosynthesis. In 2004 Moriarty engaged in a debate with Chris Phoenix over the feasibility of molecular manufacturing. In 2008 Moriarty received a grant from the British Government to examine the viability of mechanosynthesis. In this Next Big Future interview with Sander Olson, Moriarty discusses the progress that has been made during the past decade, the challenges of working with diamond, and the prospects for building components out of silicon and diamond.

Question: You began the project for experimental work on molecular mechanosynthesis about five years ago. How is the project going?

Answer: The mechanosynthesis project has actually only been running for about 2.5 years now and the initial goal was to explore the possibility of atom-by-atom assembly on diamond surfaces, i.e. to test the viability of Drexler’s original vision of making components out of diamond. But as Drexler himself recently pointed out diamond is a very difficult material to work with. As a result, in Nottingham we have a parallel effort focused on silicon, which is much, much easier to work with than diamond. For example, we only very recently achieved atomic resolution using non-contact atomic force microscopy on a hydrogen-passivated diamond surface. Moving beyond imaging to atomic manipulation of the diamond surface is going to be much more challenging than for silicon. …

Question: If you succeed, will that prove the viability of molecular manufacturing?

Answer: It will prove the viability of key aspects of Drexler’s mechanosynthesis ‘machine language’ – i.e. single atom chemistry driven solely by mechanical force and employing pre-determined tip structures/tip tools. By the time I retire (~ 2040!), I’d really hope that we are at the point where we could simply instruct a computer to build nanostructures, and let the computer handle all the details – no human operator involvement required. But this is very far from proving the viability of molecular manufacturing. It’s also very far from the scenario that, for example, Ray Kurzweil put forward back in 2000: “Around 2030, we should be able to flood our brains with nanobots that can be turned off and on and which would function as ‘experience beamers’ allowing us to experience the full range of other people’s sensory experiences…Nanobots will also expand human intelligence by factors of thousands or millions. By 2030, nonbiological thinking will be trillions of times more powerful than biological thinking.“

Question: So you are still a skeptic of the concept of molecular manufacturing?

Answer: I am a skeptic. I believe that the concept of molecular manufacturing – of creating macroscopic objects atom by atom for any material, is flawed. I do not believe that this technique can be scaled-up to manufacture macrosized objects for arbitrary materials. In “Nanosystems” Drexler makes a careful and clever choice of the type of system required for mechanosynthesis/molecular manufacturing, taking into account the key surface science issues. I’ve never been able to see why it is then claimed that these schemes are extendable to all other materials (or practically all elements in the periodic table), for the reasons I discussed at considerable length in my debate with Chris Phoenix.
But I want to take this opportunity to give credit to Drexler. He has been the subject of a lot of criticism – some of it rather non-scientific and ad hominem- from what might be described as the ‘traditional’ (i.e. non-molecular manufacturing) nanoscience community. Drexler deserves significant kudos for the concept at the heart of the molecular manufacturing scheme; single atom chemistry driven purely by (chemo)mechanical forces is demonstrably valid. Richard Smalley, despite raising other important criticisms of the molecular manufacturing concept, misunderstood key aspects of mechanosynthesis and put forward flawed objections to the physical chemistry underlying Drexler’s proposals.

The accomplishments of Professor Moriarty and his team certainly represent a major milestone along the road to advanced nanotechnology. It remains to be seen whether the proponents of diamond mechanosynthesis as the most direct route to developing a nanofactory (molecular manufacturing) will be able to overcome the problems underlying Moriarty’s skepticism, or whether modular molecular composite nanosystems will prove a better path. What is clear from this and other items we have reported here is that there is an abundance of promising leads that justify much greater support than is currently available for the development of advanced nanotechnology (high throughput atomically precise productive nanosytems).

Note added one day later: thanks to Robert A. Freitas Jr. for passing along this link to the YouTube version of the above mentioned video.

[...] manipulate atoms on surfaces (particularly on silicon surfaces—see for example this post and this post) is one promising alternative path for advancing nanotechnology toward productive nanosystems and [...]

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